First pass at splitting out worker-api from mill core. (#504)

This reduces the {scala,scalajs,scalanative}-worker dependency from the entirety of Mill to a much narrower `mill.api` module. This reduces the amount of classpath pollution within these workers, should mean they're much faster to download the first time, and reduces the amount of random junk they would pull in if they were to be used outside of the Mill project.

The interactions between the various *Modules and their *WorkerImpls has been narrowed down to the `*.api` modules, which only depend on other `*.api` modules.

A lot of things have been moved around; user code is unlikely to break, but it's possible some will if it references classes that have been moved around. Forwarders have been left for the few internal classes that Mill uses in it's own `build.sc`, to support bootstrapping. Third-party code which breaks should be a straightforward to fix just by updating imports

The `*.api` modules have minimal dependencies (mostly uPickle and os-lib) and minimal code. There is still a bunch of implementation code in there: some of it defining data-types that are commonly sent across the module/worker interface (`Agg`, `PathRef`, ...), and some of it just general helper functions that are needed both in modules and workers. The latter code isn't strictly API definitions, but for now is small enough it's not worth splitting into it's own module

2 files changed, 178 insertions, 0 deletions

diff --git a/main/api/src/io/github/retronym/java9rtexport/Copy.java b/main/api/src/io/github/retronym/java9rtexport/Copy.java
new file mode 100644
index 00000000..ac3615bb
--- /dev/null
+++ b/main/api/src/io/github/retronym/java9rtexport/Copy.java
@@ -0,0 +1,75 @@
+/*
+Copyright (C) 2012-2014 EPFL
+Copyright (C) 2012-2014 Typesafe, Inc.
+All rights reserved.
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+    * Redistributions of source code must retain the above copyright notice,
+      this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright notice,
+      this list of conditions and the following disclaimer in the documentation
+      and/or other materials provided with the distribution.
+    * Neither the name of the EPFL nor the names of its contributors
+      may be used to endorse or promote products derived from this software
+      without specific prior written permission.
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package io.github.retronym.java9rtexport;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.file.*;
+import java.nio.file.attribute.*;
+import java.util.EnumSet;
+
+import static java.nio.file.StandardCopyOption.COPY_ATTRIBUTES;
+import static java.nio.file.StandardCopyOption.REPLACE_EXISTING;
+
+public class Copy {
+    public static void copyDirectory(final Path source, final Path target)
+            throws IOException {
+        Files.walkFileTree(source, EnumSet.of(FileVisitOption.FOLLOW_LINKS),
+                Integer.MAX_VALUE, new FileVisitor<Path>() {
+
+                    @Override
+                    public FileVisitResult preVisitDirectory(Path dir,
+                                                             BasicFileAttributes sourceBasic) throws IOException {
+
+                        String relative = source.relativize(dir).toString();
+                        if (!Files.exists(target.getFileSystem().getPath(relative)))
+                            Files.createDirectory(target.getFileSystem().getPath(relative));
+                        return FileVisitResult.CONTINUE;
+                    }
+
+                    @Override
+                    public FileVisitResult visitFile(Path file,
+                                                     BasicFileAttributes attrs) throws IOException {
+                        String relative = source.relativize(file).toString();
+                        Files.copy(file, target.getFileSystem().getPath(relative), COPY_ATTRIBUTES, REPLACE_EXISTING);
+                        return FileVisitResult.CONTINUE;
+                    }
+
+                    @Override
+                    public FileVisitResult visitFileFailed(Path file, IOException e) throws IOException {
+                        throw e;
+                    }
+
+                    @Override
+                    public FileVisitResult postVisitDirectory(Path dir, IOException e) throws IOException {
+                        if (e != null) throw e;
+                        return FileVisitResult.CONTINUE;
+                    }
+                });
+    }
+
+}
\ No newline at end of file
diff --git a/main/api/src/io/github/retronym/java9rtexport/Export.java b/main/api/src/io/github/retronym/java9rtexport/Export.java
new file mode 100644
index 00000000..b71ca555
--- /dev/null
+++ b/main/api/src/io/github/retronym/java9rtexport/Export.java
@@ -0,0 +1,103 @@
+/*
+Copyright (C) 2012-2014 EPFL
+Copyright (C) 2012-2014 Typesafe, Inc.
+All rights reserved.
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+    * Redistributions of source code must retain the above copyright notice,
+      this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright notice,
+      this list of conditions and the following disclaimer in the documentation
+      and/or other materials provided with the distribution.
+    * Neither the name of the EPFL nor the names of its contributors
+      may be used to endorse or promote products derived from this software
+      without specific prior written permission.
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package io.github.retronym.java9rtexport;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URI;
+import java.nio.file.*;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+
+public class Export {
+    private final static Object lock = new Object();
+    private static File tempFile = null;
+
+    public static String rtJarName = "rt-" + System.getProperty("java.version") + ".jar";
+
+    public static File rt() {
+        try {
+            synchronized (lock) {
+                if (tempFile == null) {
+                    Path tempPath = Files.createTempFile("rt", ".jar");
+                    tempFile = tempPath.toFile();
+                    tempFile.deleteOnExit();
+                    tempFile.delete();
+                    FileSystem fileSystem = FileSystems.getFileSystem(URI.create("jrt:/"));
+                    Path path = fileSystem.getPath("/modules");
+                    URI uri = URI.create("jar:" + tempPath.toUri());
+                    Map<String, String> env = new HashMap<>();
+                    env.put("create", "true");
+                    try (FileSystem zipfs = FileSystems.newFileSystem(uri, env)) {
+                        Iterator<Path> iterator = Files.list(path).iterator();
+                        while (iterator.hasNext()) {
+                            Path next = iterator.next();
+                            Copy.copyDirectory(next, zipfs.getPath("/"));
+                        }
+                    }
+                }
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+            System.exit(-1);
+        }
+        return tempFile;
+    }
+
+    public static boolean rtTo(File dest, boolean verbose) {
+        try {
+            if (!dest.exists()) {
+                if (verbose) {
+                    System.out.println("Copying Java " +
+                            System.getProperty("java.version") +
+                            " runtime jar to " +
+                            dest.getParentFile() +
+                            " ...");
+                    System.out.flush();
+                }
+                dest.getParentFile().mkdirs();
+                java.nio.file.Files.copy(rt().toPath(), dest.toPath());
+                return true;
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+            System.exit(-1);
+        }
+        return false;
+    }
+
+    public static File rtAt(File dir, boolean verbose) {
+        File f = new File(dir, rtJarName);
+        rtTo(f, verbose);
+        return f;
+    }
+
+    public static File rtAt(File dir) {
+        return rtAt(dir, false);
+    }
+}
\ No newline at end of file